Humans show improvement on a wide variety of tasks. Some of this learning has been shown to be sleep-dependent and to represent plasticity of cortical regions. Specific sleep stages have been associated with improvement on different tasks. Another recently reported phenomenon of experience-dependent plasticity is that with repeated, within day practice on the same task the visual system shows a decrease in performance. This decrease has also been shown to be retinotopically specific and ameliorated with a daytime nap. Plastic changes in early visual cortex due to learning has been examined using functional magnetic resonance imaging (fMRI), and has shown significant increases in blood flow to areas of retinotopic visual cortex that are spatially aligned with learned target positions. During my post doctoral position, I will receive new training on the techniques and methods of fMRI, and examine cortical changes associated with perceptual learning and deterioration, as well as examining the role of attention on these phenomena.